Yes, I believe the 2008 Presidential Election was helped by the lengthy primary season. Because of the length of the season, the candidates were able to get more publicity and interact with citizens and each other more often than in a typical season. This led to a spirited and lively election.
The election was helped by the lengthy primary season because it gave voters time to learn more about the potential candidates and how they could resolved the issues facing America. Throughout the election many candidates came and went soon after. Candidates who did not make it to the end were heavily vetted and scrutinized by the media
The country as a whole was harmed by the prolonged primary season in 2008. The structure of presidential elections encourages animosity between the two dominant factions. In order to win your primary, you must appeal to your base and make promises that lead you away from the moderate center. It is only when you have secured your party's nomination that you can begin correcting course to regain the confidence of moderate voters. The longer primary season encourages candidates to go farther and farther from the center, so that once the national election takes place, neither candidate has made it all the way back.
Our primary seasons are way too long and in fact we begin to think about electing the next president the month after the election is completed. This puts the emphasis in politics on getting elected rather than on getting a job done to which the candidate was elected and we see how that is working out.